When cutting grass, especially with a self propelled power lawn mower, the need frequently arises to trim weeds or grass located in areas where it is difficult to have the weeds or grass cut by the mower blade. This particularly occurs around plantings, flowers, hedges, etc. Therefore, an efficient combined mower/weed or edge trimmer has long been desired to accomplish these two somewhat different cutting tasks. Moreover, it is a further desired feature that a combined driven lawn mower/weed or edge cutter be obtained which permits both cutting of the grass and trimming of the weeds or grass immediately surrounding such planting, bush, or flowers to be done simultaneously. It is a further object of this invention to permit these two tasks to be conducted simultaneously without requiring specific adjustments to be made in the mower/trimmer unit which would cause loss of time in accomplishing these two tasks. It is a further objective of this invention to provide such a power driven lawn mower/weed or grass cutter utilizing a flail (line cutting) device to perform the weed/grass trimming/edging in the aforementioned manner.
There have been many attempts in the prior art to accomplish some of the foregoing tasks by utilizing a lawn mower combination with a trimmer of some type.
Maxwell K. Ould U.S. Pat. No. 4,715,169 is directed to an edging attachment for a motor driven lawn mower comprising a plate that is bolted to the mower housing, the plate supporting a drive shaft carrying an idler pulley and a drive pulley, a drive belt inter connecting a pulley on the motor of a mower to either the idler or drive pulley, means to selectively engage either the idler or drive pulley and an edging means operating in a plane substantially perpendicular to the cutting plane of the mower. The edging means is supported by the plate via a boom and is driven by the drive shaft via a flexible spindle drive. The boom allows adjustment of the cutting angle edging means. The position of the drive shaft and pulleys is also adjustable relative to the motor of the mower.
Boyd L. Owens U.S. Pat. No. 4,170,099 is directed to a grass edger and trimmer attachment for a power mower including a vertical trimmer shaft mounted in a bearing fixed to the side of the mower housing, the trimmer shaft being driven by a pulley which is belt driven by the mower engine, trimmer shaft supporting a trimmer hub carrying flail members at a level below the skirt of the mower housing, and the attachment further including an arm hinged to the housing carrying an edger shaft with a drive roller thereon and an edger hub at its outer end with flail members fixed to the periphery of the hub, the drive roller engaging the trimmer drive pulley and being driven thereby when the arm and the edger shaft are substantially horizontal, but the arm being tiltable about the hinge to an elevated position wherein the roller is disengaged and the edger hub and flail members are raised out of operative position.
Fred J. Remer U.S. Pat. No. 4,453,372 is directed to a universal grass edger and trimmer attachment utilizing a rotary flexible drive shaft whose operating end is supported by a multi-positional boom. This boom can be equipped with a vertically cutting edger 100 which cuts in the direction perpendicular to that of the lower blade or a horizontally cutting trimmer 102 which cuts in a direction parallel thereto.
Boyd L. Owens U.S. Pat. No. 4,642,976 is directed to a lawn mower trimmer and edger attachment having a cutting head and mounting assembly for adjustably supporting the cutting head on a mower. The mounting assembly for the head permits adjustment of the height of the head above the ground, its horizontal angle with respect to the frame of the mower and the inclination of the head from a horizontal to a vertical orientation or any angle of inclination there between. At the end of the head opposite its cutting flail members, there's a quick detach joint which allows, either an electric motor to be mounted and energized through a switch by electrical power available aboard the mower, or alternatively allows a cable drive to be mounted which drives the head from a friction drive mechanism taking power from the mower engine shaft, the friction drive being selectively engagable by means of a Bowden control cable. A guard to deflect cuttings away from the operation is mounted on the cutting head.
Tyson W. Howard U.S. Pat. No. 4,152,882 is directed to a cutting assembly usable in combination with a primary drive power source such as an internal combustion engine on a lawn mower, tractor, or like assembly or alternately an electrically powered hand tool or like element whereby a plurality of cutting elements define a cutting head or remotely extendable from the power source by means of a drive cable element, drivingly interconnected through a power take off to the drive power source. A gear adjustment assembly is disposed in power transmitting relation between the power drive source and the plurality of cutting elements so as to regulate the rotational speed of the cutting elements during operation. The power take off assembly is specifically configured to be adapted for either direct drive coupling relationship to a drive shaft of the power drive source; or alternately, to accomplish frictional driving engagement therewith such that rotation of the cable drive element and accordingly the plurality of cutting elements may be readily accomplished with minor modification of the lawn mower, electrical tool or other power drive source used in combination with the vegetation cutting assembly.
James M. Parker U.S. Pat. No. 3,668,845 is directed to an improved rotary lawn mower having a self-contained power take-off arranged in one corner of the forward edge of the mower deck. An auxiliary unit, having a blade driven by a pulley and a belt extending to the power take-off, is supported from the deck and is movable between a trimming position in which the blade is substantially horizontal and an edging position in which the blade is substantially vertical. A cam means automatically compensates for distance changes between the pulley and the power take-off as the unit is moved between the trimming and edging positions.
L. H. Hansen U.S. Pat. No. 3,531,922 is directed to a trimmer and edger attachment for a power mower containing a bracket and bearings for journaling vertical and horizontal blade supporting shafts with beveled gears interconnecting the shafts. The bracket is connected with the forward end of a rotary mower adjacent to cut grass exhaust port. The vertical shaft is driven by a belt from the drive shaft of the mower.
M. E. True U.S. Pat. No. 2,771,730 is directed to a lawn mower and trimmer having in combination a wheeled carriage under which a blade is rotatably mounted in grass cutting relationship having mounted laterally on the carriage a pivoted means which carries on a free end thereof a rotatable trimmer blade. The carriage is provided with common power means for rotating the blade.
As will be evident from the foregoing references, these prior art devices are very complex compared with that of the present invention and would be more expensive to manufacture and maintain. The device of this invention is less expensive to manufacture and requires considerably less maintenance in addition to being simpler to employ, especially with respect to the flail portion of this device.